KR20210149149A - Milling device for prosthetic surgery - Google Patents

Abstract

A milling device (10) for prosthetic surgery comprising a milling tool (11) and a handler body (14). The handler body 14 has a rotational drive shaft 22 extending along a longitudinal axis Z, the milling tool 11 for rotating the milling tool 11 about the longitudinal axis Z ) is combined with

Description

Milling device for prosthetic surgery

The present invention relates to a milling device for prosthetic surgery suitable for preparing a place for a bone pore filling material or a bone space to insert a prosthesis.

In particular, the milling device of the present invention is particularly suitable for making a seat for a bone void filler for a knee prosthesis or for preparing a bone space for a shoulder joint prosthesis or hip joint prosthesis, also called a humerus prosthesis.

In orthopedic surgery for implanting prostheses, it is known that when preparation of a seat for a bone pore filling material or preparation of a seating site for a prosthesis is required, milling is required to make a hole in the bone and/or to make the seat to a desired size.

Occasionally, in fact, congenital or traumatic degenerative pathologies such as primary arthrosis, secondary arthritis due to trauma or infection, rheumatoid arthritis, inflammatory arthritis, osteonecrosis, or bone tumors, or other similar problems, generally reproduce movements similar to healthy joints. Implantation of a prosthesis that can be done is necessary.

In addition, when cancellous bone cannot support the prosthesis due to the above pathology, it is known that it is necessary to create an appropriate bone space for implantation of a skeleton or metal bone pore filler serving to support the prosthesis. This problem can be fatal, especially for knee arthroplasty and hip and shoulder arthroplasty.

A knee arthroplasty generally includes a femoral component that is attached to the distal end of the femur and a tibial component that is attached to the proximal end of the tibia.

Creating a bony space to apply an appropriate support cone, especially if correction of a previously implanted knee prosthesis is to be performed, involves first making a hole with one or more reamer devices of increasing diameter and then shaping it with an appropriate milling device. in need.

To this end, a milling device that can be used during prosthetic surgery to provide a space as above is known.

Such milling devices generally have a shaft extending along a longitudinal axis substantially coincident with an axis within the bone marrow canal, and optionally that of the tibia or femur, and a proximal end attached to the drive member and the drive member. It consists of a handler body with a distal end connected to a milling tool rotated by the

Since both the tibia and femur have an asymmetrically elongated shape, one of the major problems encountered during bone space preparation is to avoid perforation of the cortical region of the tibia and femur.

One of the disadvantages of known milling devices is the anatomy of the tibia and femur, since they are configured to form a bony space in the direction of the milling axis substantially coincident with the axis within the canal and, in some cases, the axis of the tibia or femur. that it cannot be followed.

Occasionally, to avoid perforation of the cortical region, the surgeon is forced to create a bony space of limited size, but this is particularly the case in any case where a previously implanted artificial joint has been damaged or rendered unusable, the artificial joint, the extension of the cancellous bone. may not be sufficient to ensure adequate joint stability of

Therefore, there is a need to complete a milling device for prosthetic surgery that can overcome at least one or more of the disadvantages of the prior art.

In particular, one object of the present invention is to provide a milling apparatus for prosthetic surgery capable of performing milling while preventing damage to the cortex of the bone.

Another object of the present invention is to provide a milling apparatus for prosthetic surgery that can provide stable milling for a milling axis that is different from the inner axis of the bone marrow cavity, that is, a milling axis different from the axis of the guide shaft inserted into the bone marrow canal. .

Another object of the present invention is to provide a milling apparatus for prosthetic surgery that is easy to use and is composed of a limited number of parts.

Another object of the present invention is to provide a milling apparatus for prosthetic surgery that can be cleaned and sterilized by simple assembly, operation and disassembly.

Applicants have devised, tested and implemented the present invention to overcome the shortcomings of the prior art and to obtain these and other objects and advantages.

The invention is characterized and described in the independent claims, and in the dependent claims other features of the invention or variations on the main inventive idea.

In accordance with the above objects of the present invention, a milling apparatus for prosthetic surgery includes a milling tool and a handler body having a rotational drive shaft extending along a longitudinal axis. The rotating shaft is connected to the milling tool for rotating the milling tool about a longitudinal axis.

According to one aspect of the present invention, the rotating shaft includes an angular joint rotatably coupled with the milling tool for selectively defining an inclined position of the milling tool with respect to a longitudinal axis.

According to another aspect of the present invention, a handler body is eccentrically disposed about a longitudinal axis and configured to cooperate with a milling tool to selectively define among a plurality of incline positions which is a single specific stable inclined position of the milling tool with respect to the longitudinal axis. and a guide member including a stabilizing body.

The milling apparatus for prosthetic surgery according to an embodiment of the present invention can perform milling while preventing damage to the cortex of the bone. That is, the milling apparatus for prosthetic surgery according to an embodiment of the present invention is suitable for making the seating of the bone void filler for the tibia, femur, shoulder joint, and the like.

In addition, it is possible to provide stable milling with respect to a milling axis different from the inner axis of the bone marrow canal, that is, different from the axis of the guide axis inserted into the bone marrow canal.

These and other features and advantages of the present invention will become apparent from the following description of some embodiments given by way of non-limiting example with reference to the accompanying drawings.
1 shows an exploded perspective view of a milling device for prosthetic surgery, particularly for application to a tibia, according to embodiments described herein.
FIG. 2 shows a sectional side view of FIG. 1 .
3 shows another cross-sectional side view of FIG. 1 ;
Fig. 4 shows a schematic plan view from above of the components of Fig. 1;
5 shows a schematic diagram of a possible application of a milling device for prosthetic surgery and the problem it solves.
6 shows a side view of a milling device for prosthetics, particularly for application to the tibia, according to embodiments described herein.
FIG. 7 is another side view of FIG. 6 .
FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6 .
9 is a cross-sectional view taken along line IX-IX of FIG. 7 .
10 shows an exploded perspective view of a milling apparatus for prosthetic surgery, particularly for application to a femur, according to embodiments described herein;
FIG. 11 shows a schematic sectional side view of FIG. 10 .
12 shows a side view of a milling device for prosthetic surgery, particularly for application to the femur, according to embodiments described herein;
13 is a longitudinal sectional view of FIG. 12 .
14 shows an exploded perspective view of a milling device for prosthetic surgery, in particular for application to the shoulder joint, in particular the fossa, according to embodiments described herein;
FIG. 15 shows a cross-sectional side view of FIG. 14 .
16 shows a side view of a milling device for prosthetic surgery, in particular for application to the shoulder joint, in particular the fossa, according to embodiments described herein;
17 is a longitudinal sectional view of FIG. 16 .
In order to facilitate understanding, the same reference numerals are used to refer to the same common components in the drawings where possible. It is understood that components and features according to one embodiment of the present invention may be readily incorporated into other embodiments without further description.

Reference is now made in detail to various embodiments of the invention, one or more examples of which are shown in the accompanying drawings. Each example is for the purpose of illustrating the present invention and should not be construed as limiting the present invention. For example, features shown or described in some portions of one embodiment of the invention may be employed in other related embodiments or employed to produce other embodiments of the invention. It is to be understood that the present invention includes all such modifications and variations.

Before describing the embodiments, it should be clear that the present description is not limited to the application of details of construction and arrangement of components as described in the following description using the accompanying drawings. This description is capable of providing other embodiments and of being obtained or carried out in various other ways. It should also be clear that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment described using the accompanying drawings relates to a milling device for prosthetic surgery, which is generally indicated by reference numeral 10 in the accompanying drawings.

With particular reference to the accompanying drawings, FIGS. 1 to 9 relate to a milling device 10 suitable for making a seat of a bone pore filler for a tibia, and FIGS. 14 to 17 relate to a milling device 10 suitable for making a seat for a shoulder joint prosthesis, also referred to as a humerus prosthesis.

Milling device 10 for prosthetic surgery, hereafter referred to as device 10, has a longitudinal axis Z connected with the milling tool 11 such that the milling tool 11 and the milling tool 11 rotate about the longitudinal axis Z ) and a handler body 14 having a rotational drive shaft 22 extending along it.

According to one aspect of the invention, the rotating shaft 22 is rotatably engaged with the milling tool 11 at an angle to selectively define a plurality of inclined positions of the milling tool 11 with respect to the longitudinal axis Z. It includes a joint (18).

According to another aspect of the present invention, the handler body 14 is arranged eccentrically with respect to the longitudinal axis Z and has a plurality of inclined positions being a single specific stable inclined position of the milling tool 11 about the longitudinal axis Z. a guide member 20 comprising a stabilizing body 21 configured to cooperate with the milling tool 11 to optionally define among.

The specific stabilized tilting position is for surgical application (applied to the tibia, femur or shoulder joint) with respect to the milling axis R where the milling tool 11 is tilted with respect to the longitudinal axis Z of rotation of the rotation shaft 22 . Allows rotation by a variable inclination angle (α) according to It can thus be said that the milling tool 11 is inclined with respect to the rotating shaft 22 and the handler body 14 .

In particular, the guide member 20 defines an inclination angle α such that when the shaft 22 rotates about the longitudinal axis Z, the milling tool rotates about the milling axis R.

As schematically shown in FIG. 5 , with this configuration of the device 10 , it is possible to create a bony space without damaging the cortical region 110 of the bone. Indeed, as a whole, the device 10 is used such that the longitudinal axis Z is substantially orthogonal to the tibial ablation, ie, substantially parallel to the interior of the intramedullary canal, whereas the device 10 is adapted to correspond to a particular stabilized oblique position. It forms a bone space for the angle of inclination α. Possibly, the milling tool 11 may have a profile of a rotating body obtained by rotation of a desired curve, for example a curve that approximates the internal geometry of the tibia or femur. In particular, the known milling apparatus is schematically illustrated in dashed lines, and the apparatus 10 according to the embodiment described herein is illustrated in solid lines. Obviously, known milling devices move much closer to the cortical region 110 at risk of damage.

Moreover, it allows the user to create a deeper bone space, which can ensure adequate joint stability of the prosthesis, especially in the case of severe degeneration of cancellous bone.

The milling tool 11 has a concave coupling seat 12 with a coupling pole opening 13 .

The shaft 22 has a distal end 16 connected to the milling tool 11 within a concave coupling seat 12, and an attachment to a drive member for rotating the milling tool 11 about a longitudinal axis Z. 17) with a proximal end 15 is provided.

Here and in the following description, when describing the shaft 22 of the milling device 10 , the relative terms “proximal” and “distal” are defined with reference to the perspective of the milling device 10 . Thus, “proximal” refers to the direction of engagement with the attachment 17 and “distal” refers to the direction of engagement with the milling tool 11 .

In particular, the angular joint 18 is located at the distal end 16 of the shaft 22 , the couple having degrees of freedom such that the milling tool 11 can selectively adopt a plurality of inclined positions with respect to the longitudinal axis Z. It is rotatably coupled with the ring pole opening 13 .

According to embodiments, the handler body 14 comprises a tubular handle 23 coupled coaxially with the shaft 22 in a removable manner and provided with a guide member 20 .

The tubular handle 23 is provided with a distal opening 25 and a proximal opening 26 associated with the distal end 16 and the proximal end 15 of the shaft 22 , respectively.

The tubular handle 23 has a longitudinal channel 27 penetrating from the distal opening 25 to the proximal aperture 26 for rotational engagement with the shaft 22 . Advantageously, the longitudinal channel 27 has a dimension in a direction perpendicular to the longitudinal axis Z which is larger than that of the shaft 22 , which makes it possible to prevent unwanted sliding.

Depending on a possible solution, the tubular handle 23 can be made in one piece or can be made of two separate shell-like parts that can be selectively joined to receive the shaft 22 . Advantageously, the tubular handle 23 can be made of a plastics material in order to reduce the minimum possible frictional force with the shaft 22 and the milling tool 11 .

According to the embodiments described herein, as particularly shown in FIGS. 8-9 and 13 and 17 , the size of the proximal opening 26 cooperates with the circumferential retaining edge 30 of the shaft 22 and It is slightly smaller than the size of the longitudinal channel 27 to ensure the desired position of the shaft 22 in the longitudinal axis Z direction.

Advantageously, the tubular handle 23 may, externally, have an ergonomic non-slip grip 28 to assist the user in gripping and handling it. To this end, the tubular handle 23 has a longitudinal groove 29 extending at least in the central region, possibly with a knurled surface. Also, the grip 28 may have a rounded shape to further improve its grip.

According to the embodiment described herein, shaft 22 is cannulated, ie hollow therein, parallel to longitudinal axis Z and axially positioning device 10 in the desired milling position during surgery. It has a guide channel (42) suitable for receiving the guide elements required to do so.

At least in the case of a milling device 10 for the femur and/or tibia, the guide element may generally be a reamer device used before the device 10 forms the first aperture or creates first apertures of increasing diameter. have. When the proper diameter of the hole is reached, the device 10 is prepared such that a guide element is inserted into the guide channel 42 to serve as an axial guide for the milling operation.

The guide member 20 , in particular the stabilizing body 21 , is configured to cooperate with the concave coupling seat 12 .

According to embodiments, the stabilizing body 21 is milled to define a specific stabilized inclined position of the milling tool 11 with respect to the longitudinal axis Z with reference to its eccentricity with respect to the longitudinal axis Z. It is configured to make a coupling of the same shape as the recessed coupling seat 12 of the tool 11 .

The guide member 20 is a sliding coupling configured to receive the shaped portion 40 of the shaft 22 such that the distal opening 25 and the shaft 22 can be ensured in a desired position in the longitudinal axis Z direction. seat 31 . In particular, the seat 31 is concentric with respect to the longitudinal axis Z.

The seat 31 is configured to perform a positioning action of the shaft 22 in cooperation with the positioning action performed by the circumferential retaining edge 30 . In this way, when the shaft 22 is operatively inserted into the longitudinal channel 27 , the position of the shaft 22 in the longitudinal axis Z is substantially determined. In particular, the shaped portion 40 is rotationally engaged with the seat 31 . This coupling presupposes that there is minimal space between the surface of the seat 31 and the surface of the shaped part 40 to enable functional movement.

According to embodiments, as shown for example in FIGS. 1-3 and 10-11 , the shaped portion 40 has a substantially cylindrical shape. The stabilizing body 21 has an outer surface 32 in sliding engagement with an inner surface 33 of the concave coupling seat 12 of the milling tool 11 . The outer surface 32 is defined by a cylindrical portion and is inclined with respect to the longitudinal axis Z at an angle of inclination α which substantially defines the angle of the milling axis R with respect to the longitudinal axis Z. The inner surface 33 of the concave coupling seat 12 advantageously has a cylindrical profile with a diameter slightly larger than the diameter of the cylindrical portion defining the outer surface 32 in order to ensure such a sliding fit. The sliding engagement ensures a single specific stable inclined position of the milling tool 11 with respect to the longitudinal axis Z.

The stabilizing body 21 also has a base surface 34 provided with a distal opening 25 that allows access to the seat 31 . The surfaces of the seat 31 and the outer surface 32 are connected to the base surface 34 , with a first surface connected externally and a second internally with respect to the distal opening 25 . In particular, because the stabilizing body is eccentric about the longitudinal axis Z, the distal opening 25 is not centered with respect to the base surface 34 but is concentric with the longitudinal axis Z.

As schematically shown in FIG. 4 , the base surface 34 is entirely eccentric with respect to the longitudinal axis Z and a first concentric portion 34a delimited by a dotted line with respect to the longitudinal axis Z for illustrative purposes only. ) and a second portion 34b eccentric about the longitudinal axis Z, the portions 34a and 34b being essentially a continuum of one another. The larger the second part 34b , and thereby the greater the eccentricity of the base surface 34 , the greater the angle of inclination of the milling tool 11 with respect to the longitudinal axis Z in the stable inclined position.

The base surface 34 is inclined with respect to the longitudinal axis Z by an inclination angle α corresponding to the inclination angle α of a single specific stable inclined position of the milling tool 11 with respect to the longitudinal axis Z. In the case of the milling device 10 for preparing the bone space for the prosthesis of the knee joint, the inclination angle α is about 5° in the case of the milling device 10 for tibial bones, and about 3° in the case of the milling device 10 for the femur. to be.

According to an embodiment, as shown in FIGS. 14 and 15 , the shaped portion 40 has a substantially conical shape. Further, the milling tool 11 has an inclined seat 45 inclined by an inclination angle α corresponding to the inclination angle α of a single specific stabilized inclined position of the milling tool 11 with respect to the longitudinal axis Z; A sliding crown 44 is provided. The sliding engagement ensures a single specific stable inclined position of the milling tool 11 with respect to the longitudinal axis Z. In the case of the milling device 10 for preparing the bone space for the prosthesis of the shoulder joint, the inclination angle α is about 25°.

According to embodiments, the anti-rotation restraint 19 is present at the distal end 16 of the shaft 22 and works with a coupling seat 35 provided in the concave coupling seat 12 of the milling tool 11 . are negatively coupled The anti-rotation constraint 19 is configured to angularly constrain the milling tool 11 relative to the handler body 14 so that it can rotate integrally about the longitudinal axis Z.

The anti-rotation restraint 19 is a rigid transmission tab 41 having a shape that mates with a corresponding coupling seat 35 present on the milling tool 11 for transmitting rotational motion to the milling tool 11 . ) is included.

The anti-rotation restraints 19 project radially from the profile of the shaft 22 and are advantageously diametrically opposed to each other, if more than one is present. Advantageously, in practice, there are two anti-rotation restraints 19 to ensure a better transmission of the rotational torque from the shaft 22 to the milling tool 11 . The diametrically opposed positions of the two anti-rotation restraints 19 are a plurality of the milling tool 11 tilted about the longitudinal axis Z by rotating horizontally in a plane orthogonal to the plane passing through the anti-rotation restraint 19 . Allows to adopt selectively among the positions, in particular to adopt a single specific stabilized inclined position defined by the concave coupling seat 12 of the milling tool 11 and the identically shaped engagement of the stabilizing body 21 .

The anti-rotation restraint 19 is removably coupled to a coupling seat 35 made corresponding to the coupling pole opening 13 of the milling tool 11 .

The coupling seat 35 is substantially radial with respect to the longitudinal axis Z and is configured to ensure the necessary constraint to transmit rotational torque from the shaft 22 to the milling tool 11 .

Advantageously, the number of coupling seats 35 matches the number of anti-rotation restraints 19 . This avoids possible assembly errors and ensures a single and secure connection of the milling tool 11 on the shaft 22 .

According to embodiments, the angular joint 18 has at least one convex curve 24 disposed about the longitudinal axis Z.

Advantageously, the angular joint 18 has at least two or more convex curvatures 24 arranged diametrically opposite to the longitudinal axis Z.

According to the embodiments described herein, the anti-rotation constraint 19 is arranged about the longitudinal axis Z alternately with the convex curves 24 .

The convex flexure 24 projects radially from the profile of the shaft 22 at a position diametrically opposed to the profile of the anti-rotational restraint element 19 , each formed concave having a shape that mates with the shape of the convex flexure 24 . configured to engage with the portion 36 .

Advantageously, the forming recess 36 allows for an elastic snap-in engagement that uniquely determines the axial position of the milling tool 11 . Indeed, when the milling tool 11 engages the shaft 22 , the convex curve 24 is forced to removably engage the forming recess 36 .

Advantageously, the at least one or more convex curves 24 are sphere portions.

According to embodiments, the angular joint 18 comprises a resilient keying tab 37 , each provided with one of the convex curves 24 .

Each keying tab 37 extends in the longitudinal axis Z direction, and has a tip 39 provided with a convex curve 24, and a base stably attached to a shaft 22 opposite the tip 39. 38) has. Advantageously, only the base 38 is securely attached to the shaft 22 so that the keying tab 37 can flex relative to the base 38 when pressure is applied to the tip 39 .

The keying tab 37 may be bent in a direction orthogonal to the longitudinal axis Z. To this end, the angular joint 18 has a chamber 43 configured to penetrate the shaft 22 vertically and allow the keying tab 37 to flex while at least engaged with the milling tool 11 .

It will be apparent that modifications and/or additions of parts may be made to the prosthetic surgical milling tool as described heretofore without departing from the scope and scope of the present invention.

Further, although the present invention has been described with reference to some specific examples, a person of ordinary skill in the art will have the characteristics set forth by the claims and thus all fall within the field of protection defined by them, prosthetic milling It is evident that various other equivalent forms of the tool may be obtained.

In the claims that follow, the sole purpose of reference in parentheses is to facilitate reading and should not be regarded as a limiting factor with respect to the field of protection claimed in the specific claims.

10 Milling device for prosthetic surgery
11 milling tools
12 concave coupling seat
13 Coupling pole opening
14 Handler body
15 proximal end
16 distal end
17 attachment
18 angle joint
19 Anti-Rotation Constraints
20 no guide
21 stabilization body
22 rotary drive shaft
23 tubular handle
24 convex bend
25 distal opening
26 proximal opening
27 longitudinal channel
28 Non-Slip Grip
29 longitudinal groove
30 Circumferential holding edge
31 Sliding Coupling Seat
32 outer surface
33 inner surface
34 base surface
35 coupling spot
36 molded recesses
37 Elastic Keying Tab
38 bass
39 tips
40 shape parts
41 Rigid Transmission Tab
42 guide channel
43 chamber
44 connecting crown
45 sloping spot

Claims (11)

milling tool (11);
for prosthetic surgery comprising a handler body (14) connected to the milling tool (11) for rotating the milling tool (11) and having a rotational drive shaft (22) extending along a longitudinal axis (Z) In the milling apparatus,
The rotating shaft 22 has an angular joint 18 rotatably coupled with the milling tool 11 for selectively defining a plurality of inclined positions of the milling tool 11 with respect to the longitudinal axis Z. including,
The handler body 14 is arranged eccentric with respect to the longitudinal axis Z and the milling tool 11 is tilted with respect to the longitudinal axis Z, which is a single specific stable inclined position of the milling tool 11 . a guide member (20) comprising a stabilizing body (21) configured to cooperate with said milling tool (11) to selectively define among a plurality of incline positions capable of self-rotation about a true milling axis (R); A milling device for prosthetic surgery, characterized in that it comprises. According to claim 1,
The stabilization body 21,
To define the single specific stabilized inclined position of the milling tool 11 with respect to the longitudinal axis Z, with reference to the eccentricity with respect to the longitudinal axis Z, the same as the milling tool 11 A milling device for prosthetic surgery, characterized in that configured to obtain a shaped coupling. 3. The method of claim 1 or 2,
The handler body 14,
and a tubular handle (23) coaxially coupled with said shaft (22) in a removable manner and comprising said guide member (20). 4. The method of claim 1, 2 or 3,
an anti-rotation constraint (19) located at the distal end (16) of the shaft (22) and operatively engaged with a coupling seat (35) provided in the concave coupling seat (12) of the milling tool (11); Milling device for prosthetic surgery, characterized in that it further comprises. The method of any preceding claim,
The angle joint 18,
Milling device for prosthetic surgery, characterized in that it has at least one convex curve (24) arranged about the longitudinal axis (Z). 6. The method of claim 5,
Milling device for prosthetic surgery, characterized in that the at least one or more convex curves (24) are spherical sections. 7. The method according to claim 5 or 6,
Milling device for prosthetic surgery, characterized in that the angular joint (18) has at least two or more of the convex curves (24) arranged diametrically opposite to the longitudinal axis (Z). 8. The method according to any one of claims 5 to 7,
and each said angular joint (18) comprises an elastic keying tab (37) provided with one of said convex curves (24). 9. The method of claim 4 in combination with any one of claims 5 to 8,
The anti-rotation constraint element 19 is,
Milling device for prosthetic surgery, characterized in that it is arranged around the longitudinal axis (Z) alternately with the convex curves (24). 10. The method of claim 9,
The anti-rotation constraining element 19 is,
and a rigid transmission tab (41) having a shape to mate with a coupling seat (35) present on the milling tool (11) for transmitting rotational motion to the milling tool (11) , milling devices for prosthetic surgery. The method of any preceding claim,
The stabilization body 21,
an outer surface (32) in sliding engagement with an inner surface (33) of said concave coupling seat (12) of said milling tool (11);
The outer surface 32 is
inclined with respect to the longitudinal axis Z at an inclination angle α defined by a cylindrical portion and substantially defining the angle of the milling axis R with respect to the longitudinal axis Z,
The inner surface (33) of the concave coupling seat (12) comprises:
A milling device for prosthetic surgery, characterized in that it has a cylindrical profile having a diameter slightly larger than the diameter of the cylindrical portion defining the outer surface (32).

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